Uterine fibroids are growths made of fibrotic cells and other tissue that develop within the wall of the uterus.
Fibroids may grow as a single tumor or in clusters. A single fibroid can be microscopic in size or can grow to eight inches or more across. In many cases, a single uterus can contain many fibroids. Most fibroids range from about the size of a large marble to slightly smaller than a baseball. Bunches or clusters of fibroids are often of different sizes. Not all fibroids grow, and some may shrink, or remain constant over time.
Health care providers categorize fibroids based on where in the uterine wall they grow:
- Submucosal fibroids grow just underneath the uterine lining.
- Intramural fibroids grow in between the muscles of the uterus.
- Subserosal fibroids grow on the outside of the uterus.
Some fibroids grow on stalks that grow out from the surface of the uterus or into the cavity of the uterus. These are called pedunculated fibroids.
Many women may have no symptoms of fibroids. Though for others, uterine fibroids can cause uncomfortable or sometimes painful symptoms, such as:
- Heavy bleeding or painful periods
- Bleeding between periods
- Feeling “full” in the lower abdomen (belly)—this is sometimes called “pelvic pressure”
- Frequent urination (caused by a fibroid pressing on the bladder)
- Pain during sex
- Lower back pain
- Reproductive problems, such as infertility, multiple miscarriages, and early onset of labor during pregnancy
- Obstetrical problems, such as increased likelihood of cesarean section
Estimates suggest that over 70% of women may have fibroids in their lifetimes, and hundreds of thousands of women seek treatment for fibroids each year. About 200,000 women each year choose to have surgery to treat fibroids by removing their uterus.
Fibroids usually grow in women of childbearing age. In women 25 to 44 years old, about 30% have symptoms of fibroids.
Several factors affect a woman's risk for having uterine fibroids. Factors that increase a woman’s risk of developing fibroids include:
- Age older than 40 years
- African American race
- Family history of uterine fibroids
- High blood pressure
- No history of pregnancy
Factors that lower risk of fibroids:
- Pregnancy (the risk decreases with increasing number of pregnancies)
- Long-term use of progestin-only birth control pills or oral contraceptives
- Use of the birth control shot (depot medroxyprogesterone acetate [DMPA])
Diagnosis of Uterine Fibroids
Unless you have symptoms, you probably won’t know that you have uterine fibroids.
Sometimes, health care providers find fibroids during a routine gynecological exam. During this exam, the health care provider checks the size of your uterus by putting two fingers of one hand into the vagina while using the other hand to press lightly on your abdomen. If you have fibroids, your uterus may feel larger than normal or it may feel irregularly shaped. But even small fibroids in the uterus may cause considerable symptoms and heavy periods leading to anemia. Smaller fibroids which can’t be found through a routine manual examination can be detected with ultrasound.
If your health care provider thinks you have fibroids, he or she may use one or more types of imaging technology—machines that create a picture of the inside of your body—to confirm the diagnosis.
Some common types of imaging technology are:
- Ultrasound, which uses sound waves to form the picture
- Saline infusion sonography, which uses an injection of salt solution into the uterus to help create the ultrasound image
- Magnetic resonance imaging (MRI), which uses magnets and radio waves to create the picture
- X-rays, which use a form of electromagnetic radiation to “see” into the body
- Computed tomography (CT) or computer-assisted tomography (also called a “CAT” scan), which scans the body with X-rays from many angles to create a more complete picture
Treatment for uterine fibroids
There are medical treatments for uterine fibroids and surgical treatments for uterine fibroids.
Your health care provider will consider a number of things before recommending treatment for your fibroids, including:
- Your age
- Your general health
- The severity of your symptoms
- The location of the fibroids
- The type and size of the fibroids
- Whether you are pregnant now or want to get pregnant in the future
If you have uterine fibroids but have no symptoms or problems, you may not need treatment. Each year, your health care provider will check the fibroids at your routine gynecological exam to see if they have grown. If you are close to menopause, your health care provider may find that your fibroids are shrinking, which is common during and after menopause.
Medical Treatments for Fibroids
Your health care provider may suggest medical treatments to reduce the symptoms of fibroids or to stop the growth of fibroids. These treatments are less invasive than surgery. However, if the medical treatments are not helpful, then surgery is often recommended. Certain medical treatments to reduce fibroid size and blood loss may be used to help the surgery succeed.
Common medical treatments for fibroids include:
- Pain medication. Over-the-counter or prescription medication is often used for mild or occasional pain from fibroids.
- Birth control pills or other types of hormonal birth control. These medications control heavy bleeding and painful periods. However, this therapy can sometimes cause fibroids to grow larger.
- Progestin-releasing intrauterine device (IUD). The IUD, also called intrauterine contraception (IUC), reduces heavy and painful bleeding but does not treat the fibroids themselves. It is not recommended for women whose fibroids result in an extremely large uterine cavity.
- Gonadotropin-releasing hormone agonists (GnRHa). These medications block the body from making the hormones that cause women to ovulate and have their periods. The medications also reduce the size of fibroids. Because this treatment can cause side effects that mimic the symptoms of menopause (such as hot flashes, night sweats, and vaginal dryness) and bone loss (which weakens the bones), it is not meant for long-term use. Most of the time, these medications are used for a short time to reduce the size of fibroids prior to surgery, or to treat anemia. If you need to take this treatment for a long time, the doctor may prescribe medication to put back the hormones that were blocked.
- Antihormonal agents. These drugs, which include mifepristone, can slow or stop the growth of fibroids, but the U.S. Food and Drug Administration has not approved their use for treating fibroids.
Medical treatments may give only temporary relief from the symptoms of fibroids. Once you stop the treatment, fibroids often grow back and symptoms return.
Medications are generally safe, but they can have side effects, some of which may be serious. Be sure to talk to your health care provider about the possible side effects of any medical treatment you consider.
Surgical Treatments for Fibroids
If you have moderate or severe symptoms of fibroids, surgery may be the best treatment for you.
Surgery can be a major procedure or a minor one. The type of surgery depends on the size, location, and number of fibroids present, and your desire to bear children in the future. Sometimes, there are a variety of surgical options to choose from. Talk to your health care provider about the different types of surgical treatments and about the possible risks, side effects, and recovery time of each procedure.
The current surgical treatments for fibroids are listed below.
- Uterine artery embolization (UAE)
- Endometrial ablation
- Magnetic resonance imaging (MRI)-guided ultrasound surgery
Pregnancy and Uterine Fibroids
If you have fibroids, you may still be able to get pregnant. Many women who have fibroids get pregnant naturally. Advances in treatments for fibroids and for infertility have greatly improved the chances for a woman to conceive. If you have fibroids and wish to become pregnant, it is wise to consult with a knowledgeable provider about the location of the fibroids and possible related problems with establishment or growth of a baby in the womb.
However, some women with fibroids do have trouble getting pregnant. Current research suggests that submucosal and intramural fibroids—fibroids that change the shape and size of the uterine cavity—seem to affect a woman's ability to get pregnant, even with in vitro fertilization. These fibroids may reduce fertility by as much as 70%. However, if the fibroid is treated, fertility may be restored.
Fibroids can also cause pregnancy complications, such as miscarriage, preterm delivery, abnormal position of the fetus, and the need for cesarean (C-section or surgical) delivery. Fibroids can also increase the risk of heavy bleeding after delivery.
Reference: National Institutes of Child Health and Human Development